Air purification systems

ABSTRACT

A ventilating hood and duct structure for stoves wherein a baffle and water spray arrangement within the hood forces the smoke to pass through successive water curtains. Grease and other impurities are drained from the hood structure through a rectangular trough which overlies the fire area.

United States Patent [191 Costarella et al.

[54] AIR PURIFICATION SYSTEMS [75] Inventors: Nino F. Costarella; Anthony A.

Giuffre, both of Milwaukee, Wis.

[73] Assignee: Ninos, Inc., Milwaukee, Wis. 22 Filed: Sept. 30, 1971 [21] Appl. No.: 185,202

Related U.S. Application Data [62] Division of Ser. No. 839,383, July 7, 1969, Pat. No.

[52] U.S. Cl ..55/228, 55/260, 55/DIG. 36, 98/115 k [51] Int. Cl. ..'.....B01d 47/06 [58] Field of Search ..55/93, 94, 22 B,

55/227, 228, 23.8, 240, 241, 260, DIG. 36; 98/l15K,l15;26l/5,l17

[56] References Cited UNITED STATES PATENTS 1,223,082 4/1917 Lissauer ..55/227 51 May 8, 1973 2,265,227 12/1941 Coffey ..261/117 3,018,847 1/1962 Stanly ..55/24l 3,100,809 8/1963 Baker, Jr. ..55/DIG. 36 3,324,629 6/1967 Graswich et al ..55/223- 3,518,817 7/1970 Dell Agnese et al. ..26l/l l7 FOREIGN PATENTS OR APPLICATIONS 535,484 4/1941 Great Britain 55/228 Primary Examiner-Bernard Nozick Attorney-Robert C. Brown, Jr. era].

[57] ABSTRACT A ventilating hood and duct structure for stoves wherein a baffle and water spray arrangement within the hood forces the smoke to pass through successive water curtains. Grease and other impurities are drained from the hood structure through a rectangular trough which overlies the fire area.

6 Claims, 2 Drawing Figures I I 200 20a Patented May 8,1973 3,731,462

2 fSheets sheet 1 I A 'm 51w as an l. Giza/f s AIR PURIFICATION SYSTEMS This application is a division of our copending application, Ser. No. 839,383, filed July 7, 1969 now U.S. Pat. No. 3,628,311.

The present invention is directed to new and useful improvements in ventilating and air purifier structures associated with cooking stoves.

Various forms of baffle and grease collecting trough structures have been known for use with stoves for many years. The baffle structures are arranged in the ventilators. Baffles have been arranged within the ventilating duct and hood structure to cause smoke from the stove to follow various paths so that grease particles carried by the smoke may be deflected against baffle surfaces from whence they may drain into some form of a collecting trough. In some of these prior structures Water sprays have been associated with the duct structure so that the smoke must pass through a mist or curtain of water which serves to remove soot and grease particles entrapped in the air stream in a manner known to the gas purification and paint spray booth arts.

Units of this general type have been proposed for use with barbecue-like fires in which charcoal is burned to produce the heat for the stove grillpThe smoke emitted from such fires is usually heavily laden with soot and grease particles and prior hood and baffle structures have not been as effective as desired in removing soot, grease and other impurities from the air flow.

With the foregoing in mind the major purposes of the present invention are to arrange. a ventilating hood,

baffle and duct structure for use with charcoal fires-in such a manner that water sprays within the duct work are highly effective in removing grease and soot particles from the air stream carrying the smoke from the fire and in such a manner as to minimize fire hazards,

while arranging such a system for use with or without cleansing detergents for the water spray and arranging the system so that impurities are easily Separated from the water circulating system.

1 These and other purposes will become more apparent in the course of the ensuing specification and claims when taken with the accompanying drawings in which: 1

*FIG. 1 is a front view of a ventilating hood and duct structure incorporating the principles of the present invention; and e FIG. 2 is a side view FIG. 1.

Like elements are designated by like characters throughout the specification and drawings.

With specific reference now to the drawings, and in the first instance to FIG. 1, the numeral generally designates a stove which has the customary grill 11 positioned above burners or an open flame produced by charcoal. The stove has a back wall comprised of firebrick 12 extending upwardly above the grill 11 at of the structure illustrated in the rear of the stove. It should be understood that the stove illustrated in the drawings is intended to be representative of well known and conventional forms ofstoves or broilers.

In accordance with the present invention, a ventilating hood generally designated 13 is positioned above the stove structure. The hood 13 may rest upon the upper wall of the firebrick 12. It may be supported from a wall, ceiling or other means. The hood is downwardly open and is generally defined by a rear wall wall 17 which extends vertically from the firebrick 12, a front wall 15 which is downwardly and forwardly inclined, and side walls 16 and 16a which extend between the front and rear walls. The side walls 16 and 16a are positioned a distance apart sufficient to span the entire length of the griil, although the hood may span a greater or lesser portion of the area of the grill.

The hood also includes a top wall 17 which spans the w front, rear and side walls in an overlying relation. An outlet duct 18 is joined to the top wall at a point generally centrally of the top wall 17 and serves to exhaust smoke from the hood to the exterior. A ventilating fan 18a may be positioned in the duct 18 for purposes of inducing a flow of air through the bottom of the hood and outwardly through the 'duct 18.

In accordance with the present invention, the lower portion of the front wall 15 has a downwardly and outwardly convex lower portion which terminates in a trough 20. Trough 20 is generally rectangular when viewed in plan and extends completely around the rear wall, front wall, and both side walls. The space within the front, rear and side portions 20a, 20b, 20c and 20d of the trough defines an air flow or smoke flow space for entry into the ventilating hood. In further accordance with the invention, a first baffle structure 21 is positioned in overlying relation to the flow area between the walls of the trough. Baffle 21 extends from the rear wall 14 at its point of juncture with the rear section 20b of the trough to a point spaced above the forward portion of the trough section 20a. This baffle structure extends for the entire length of the hood and between both side walls 16 and 16a. Baffle 21 is preferably formed with a first downwardly and forwardly concavely curved portion 2111 which merges with a plane section 21b. Another baffle section 22 is coplanar'with section 21 and extends upwardly and rearwardly from the point of juncture of the portions 21a and 21b to a point of connection with the rear wall 14. The baffle portions 21b and 21amay be formed as a A second baffle 23 projects inwardly from the downwardly and forwardly inclined portion of the front wall- 15 and projects inwardly to a location spaced above the baffle portion 21b. Baffle 23 also extends for the full length of the hood and between the side walls 16 and 16a. Baffle 23 is preferably formed with a more or less V-shaped cross-section as illustrated with the sides of the V being curved gradually; The forward side 23a of the baffle 23 preferably has a downwardly concave curvature formed generally as a continuation of the curvature of the lower portion 1-9 of the front wall. The positioning of the baffle 23 above the baffle 21b together with the curvature of the front wall surface portion 19 and surface portion 23a of baffle 23 forces .air flowing upwardly within the baffle to reverse jacent the inner surface of the front wall 13 and at a location above the baffle 23. This header 24 has branch supply pipes 25 extended inwardly to a position generally midway between the front and rear walls and each branch supply pipe carries a forwardly directed nozzle 26 as illustrated. Five such branch supply pipes 25 and nozzles 26 are positioned along the length of the hood at locations such that the nozzles are equally spaced along the length of the hood for dispersal of water generally uniformly throughout the length of the hood.

The nozzles 26 are of a type which produces a fine mist-like spray of water in a generally conical pattern. The nozzles 26 are directed toward the rearwardly facing surface 23b of baffle 23. The spray, which, as indicated in dotted lines, impinges against the inner surface of the front wall, against baffle surface 23b and against the upper surface of baffle 21b. Some of the mist may be directed through the space between the lower edge of baffle 23 and the upper surface of baffle portion 21b and against the inner surface of the lower portion 19 of the front wall.

An opening may be provided in the front wall 15 of the hood at an area overlying the supply pipe 24 and may be closed by a cover 27 so as to permit inspection of the interior of the assembly from time to time.

With the nozzles positioned as illustrated and sup plied with water, air or smoke flowing upwardly within the hood structure is forced to pass through the mistlike spray emitted from the nozzles throughout the length of the hood. A water curtain is formed between the lower edge of baffle 23 and baffle 21 as designated at C by reason of water draining down the baffle surface 23b to the baffle 21b. Another water curtain C is defined between baffle 21b and the forward trough section a. Water draining from the curtain C and from the inner surface of the lower portion 19 of the front wall drains into the trough 20 from whence it may be removed by a drain pipe 28.

In the operation of the structure as thus described, water is constantly circulated to the nozzles 26 and the nozzles emit the mist-like spray to produce the water curtain C and C. Air and smoke, which from a charcoal broiler isrelatively heavily laden with soot and grease particles, is forced to flow upwardly within the space defined by the walls of the trough whereupon the baffle 21 constrains the air to flow in a more or less curvilinear and lateral direction through the lower water curtain C. The air and smoke then is forced to reverse direction for flow through the water curtain C. The air and smoke then is constrained to flow through the fine mist-like spray emitted from the nozzles 26. The flow of the air and smoke through the successive water curtains C and C causes the water curtains to collect the particles of grease and soot, dirt and the like which are carried in the smoke and air stream. Final cleansing of the smoke and air stream occurs as the smoke and air stream passes through the mist-like spray from the nozzles 26. The impurities deposited in the water are carried downwardly by The baffle structures to a point of drainage into the trough 20.

The drain water may be continuously emptied into some suitable drain system or it may be circulated through a separating system so that the impurities are cleaned from the water and the water is then recirculated through the nozzles 26. For example, drain line 28 may lead to a receptacle 29. Receptacle 29 may have a relatively fine screen 30 disposed across the lower portion thereof so as to collect impurities thereon. A fresh water supply line 31 leads from the bottom of the receptacle through a check valve 32 and through a recirculating pump 33 which recirculates the cleaned water through a supply line 34 to the header 24. The upper part of the receptacle may include an overflow outlet 35 to drain off accumulated particles of grease, soot, dirt or the like. A float valve 36 controls the level of fluid within the receptacle as by periodically opening a makeup water line 37 to insure a predetermined level of liquid within the receptacle 29.

Detergents may be added to the water supply line 34 so that the water carries a detergent therein for mixing with the grease, soot and dirt particles. This provides a continuous cleansing action to the interior of the hood structure and serves to initially break down particles of grease, soot and dirt to an extent such that they are efficiently carried with' the water stream. The accumulated sludge defined by the mixture of detergent, grease, dirt and soot floats at the top of the liquid body in the receptacle 29 and is continuously removed therefrom by the drain 35.

Structures as disclosed herein are highly effective in removing particles of grease, soot, dirt and the like from the smoke and air stream emitted above charcoal fires. The structures are also effective to remove odors from the air stream before it is passed to the exterior.

The hood structure is kept relatively free of grease and soot deposits which, if not eliminated, produce a fire hazard. The constantly circulated water helps to minimize and restrict any flame above the grill and serves to substantially prevent the flame from ever reaching the exterior of the building through the hood structure. The annular trough structure provides cooling'of all of the walls of the hood structure by virtue of heat transfer with the water flowing down the walls and in the troughs. Additional cooling is provided by the water spray in the air space within the hood. This further minimizes the possibility of grease and soot igniting within the hood because of heat transfer from the structure.

The drain system may be operated so that a substantial body of liquid is maintained in the trough as illustrated in the drawings. It is preferred, however, to operate the drain system so that only a thin film of liquid is present in the bottom of the trough.

We claim:

1. A ventilating hood and duct structure for use with cooking stoves and the like including a downwardly open hood having front, rear and side wall portions, an upwardly open trough positioned within said hood at the lower portion of said hood and extending around the front, rear and side wall portions of said hood, said trough defining the margins of an open inlet between portions of said trough and formed and adapted for a superimposed vertical alignment with the fire area of a cooking stove, an outlet duct fixed to the upper portion of said hood and communicating with the interior of said hood, means for inducing air flow through said inlet and to said outlet, a baffle surface positioned above said trough and extending over the entire air flow area of the front, rear and side wall portions of said trough and in overlying and spaced relation to the trough and the open inlet, said baffle extending from the rear wall of the hood toward the front wall and being spaced from said front wall to define a flow space between the front edge of said baffle and said front wall, said baffle being downwardly and forwardly inclined with respect to the front and rear walls of said hood, nozzle means directed towards the front wall and spaced above said baffle within said hood for directing a water spray between the front-wall of said hood and the upper surface of said baffle to provide a water scrubbing curtain between said baffle and said trough and a secondary water scrubbing action between said front wall and said baffle, the forward edge of said baffle being positioned over the portion of said trough at the front of said hood, said water spray providing a cooling and washing effect on the front wall portion of said hood and on said baffle.

2. The structure of claim 1 wherein said nozzle means includes a plurality of nozzles equally spaced along the length of said hood and directed toward the front wall portion of said hood.

3. The structure of claim 1 characterized by and including water circulating and impurity separating means for continuously circulating water through said nozzle means, draining water and impurities from said trough, removing impurities from said water, and returning said water to said nozzles.

4. The structure of claim 1 wherein said baffle is downwardly concave adjacent the rear wall of said hood.

5. The structure of claim 1 characterized by and including a second baffle projecting inwardly from the front wall portion of said trough to a point overlying and spaced from said first named baffle so as to provide a water curtain and air flow space between said baffles.

6. The structure of claim 1 wherein said second named baffle is curved to provide a downwardly facing concave surface portion and a second concave curvilinear portion which faces said nozzle means. 

1. A ventilating hood and duct structure for use with cooking stoves and the like including a downwardly open hood having front, rear and side wall portions, an upwardly open trough positioned within said hood at the lower portion of said hood and extending around the front, rear and side wall portions of said hood, said trough defining the margins of an open inlet between portions of said trough and formed and adapted for a superimposed vertical alignment with the fire area of a cooking stove, an outlet duct fixed to the upper portion of said hood and communicating with the interior of said hood, means for inducing air flow through said inlet and to said outlet, a baffle surface positioned above said trough and extending over the entire air flow area of the front, rear and side wall portions of said trough and in overlying and spaced relation to the trough and the open inlet, said baffle extending from the rear wall of the hood toward the front wall and being spaced from said front wall to define a flow space between the front edge of said baffle and said front wall, said baffle being downwardly and forwardly inclined with respect to the front and rear walls of said hood, nozzle means directed towards the front wall and spaced above said baffle within said hood for directing a water spray between the front wall of said hood and the upper surface of said baffle to provide a water scrubbing curtain between said baffle and said trough and a secondary water scrubbing action between said front wall and said baffle, the forward edge of said baffle being positioned over the portion of said trough at the front of said hood, said water spray providing a cooling and washing effect on the front wall portion of said hood and on said baffle.
 2. The structure of claim 1 wherein said nozzle means includes a plurality of nozzles equally spaced along the length of said hood and directed toward the front wall portion of said hood.
 3. The structure of claim 1 characterized by and including water circulating and impurity separating means for continuously circulating water through said nozzle means, draining water and Impurities from said trough, removing impurities from said water, and returning said water to said nozzles.
 4. The structure of claim 1 wherein said baffle is downwardly concave adjacent the rear wall of said hood.
 5. The structure of claim 1 characterized by and including a second baffle projecting inwardly from the front wall portion of said trough to a point overlying and spaced from said first named baffle so as to provide a water curtain and air flow space between said baffles.
 6. The structure of claim 1 wherein said second named baffle is curved to provide a downwardly facing concave surface portion and a second concave curvilinear portion which faces said nozzle means. 